I was on lunch on my iPhone so that was the short version. Here's the long. A power inverter takes DC power(most commonly 12 volt) and converts it to AC power by generating it's own wave form. Here in the US a power inverter would produce 60hz power to feed standard US products. In Europe a power inverter would produce 50hz power to feed their standard products. A rectifier converts AC power to DC power. So if you take your 120V 60hz American power and feed it into a rectifier producing 12V DC power, you can then feed that 12V DC power into a European power inverter which will produce 50hz AC power. Obviously you would need to convert the European plug on the inverter to an American plug, but thats no big deal.

To take this a step further, you could modify the inverter to produce whatever frequency, and hence whatever RPM you desire. The frequency of the wave produced by a power inverter is generally controlled by one resistor. Change the value of that resistor and you change the frequency of output. This exact method is used in some variable frequency drives by using a variable resistor of some sort in the circuit, but since you want a fixed RPM a fixed resistor would work. Here is a link that discusses doing exactly this to controll motor speed for a different purpose:

Yeah that is true that the euro inverters will be 220v but the Santos runs at 220 drawing 600 watts. Somebody needs to check with them and see if it can handle that as wired for the American market. It draws 600 watts at 220 and a 900 watt inverter can be had on amazon for $85.

The inverter has to be large enough to handle the start surge current. The 2000 watt inverter is 3 times the running wattage to handle the start. Also, is the $85 inverter on Amazon 50 HZ @ 120 volts ? I'll bet it isn't a pure sine wave supply. I think the pure sine wave design is part of the high cost.

Thanks for the cost Bill. I never thought to look on Amazon. What don't they carry?

I also looked at the Santos schematics, the 220 model is wired very differently.

Apparantly 2:1 transformers are pretty common for converting 220/50 into 110/50. Most american devices will run at 110/50, so they can be used in europe with the converter. That said this would become quite the daisey chain. It would go:

To me that is a lot of electrical equipment for a little gain. Before doing all that I would buy a cheap american power inverter and have somebody with electrical knowledge modify it to run at the exact frequency you want to really dial this in. If I had a Santos I would forge the path. Just for the sake of it, this would go:

A power inverter takes DC power(most commonly 12 volt) and converts it to AC power by generating it's own wave form. Here in the US a power inverter would produce 60hz power to feed standard US products. In Europe a power inverter would produce 50hz power to feed their standard products. A rectifier converts AC power to DC power. So if you take your 120V 60hz American power and feed it into a rectifier producing 12V DC power, you can then feed that 12V DC power into a European power inverter which will produce 50hz AC power. Obviously you would need to convert the European plug on the inverter to an American plug, but thats no big deal.

To take this a step further, you could modify the inverter to produce whatever frequency, and hence whatever RPM you desire. The frequency of the wave produced by a power inverter is generally controlled by one resistor. Change the value of that resistor and you change the frequency of output. This exact method is used in some variable frequency drives by using a variable resistor of some sort in the circuit, but since you want a fixed RPM a fixed resistor would work. Here is a link that discusses doing exactly this to controll motor speed for a different purpose:

The inverter has to be large enough to handle the start surge current. The 2000 watt inverter is 3 times the running wattage to handle the start. Also, is the $85 inverter on Amazon 50 HZ @ 120 volts ? I'll bet it isn't a pure sine wave supply. I think the pure sine wave design is part of the high cost.

Dear friends, I thank all of you for your contributions toward solving this issue. it seems to me that some of us involved in this Santos-fork-speed project hold pieces of the puzzle! Moreover, per my research, it appears that Mr. Scott_r and some other respectful individuals are right about futility of Variac, which merely increase or decrease the voltage. With my very limited knowledge of electronics, today I spent about four hours of research, trying to have some rudimentary understanding in respect to the electronic principles underlying armature speed. The followings are the tentative results of my research.

1. According to the identification plate attached to the bottom of my Santos mixer, the following are the specifications of the mixer:

2. According to the manual that came with my Santos mixer (type 18V1), its electronic motor is run by alternating currents (AC). Further, its motor or armature is a "single phase asynchronous [or 'induction'] motor".

3. It seems that the single-phase asynchronous motor of Santos generates a rotating magnetic field by using one of the following methods:

(a) "Capacitor start motor", which is a type of "Split-phase induction motor" that is commonly used in home appliances such as washing machines, clothes dryers, fans, and etc. A "capacitor start motor" is equipped with a starting capacitor inserted in series with the startup winding, creating an LC circuit which is capable of a much greater phase shift and, hence, a much greater starting torque. (b) "Permanent-split capacitor motor" aka "capacitor start and run motor" which is commonly used in air blowers, ceiling fans, and other cases where a variable speed is desired.

4. Assuming that the Santos mixer uses the "capacitor start motor" (method "a") for generating a rotating magnetic field within its armature, the speed of the motor is primarily controlled by the "number of pole pairs" and the "frequency" of the supply voltage. In other words, it appears that the motor's RPM (rotations per minute) is primarily determined by two factors: (1) the number of poles in the stator winding, and (2) the frequency of the AC supply.

I do not believe changing the "number of poles in the stator winding" is a viable option, which consists in physically modifying it, if possible at all. However, I presume I can manage to change the "frequency" from 60 Hz to 50 Hz while maintaining a voltage of 100-120 volts. And, to accomplish that one needs a specialized converter, that can be quite expensive. One such device is "APT VariPLUS MODEL 105", which is probably an overkill. Luckily, I have found someone in San Diego who is willing to sell his VariPLUS to me for $300.00. (The retail price is about $995.00.) At this point, I do not know if this is a safe, sound, and effective solution. I will know more about the device tomorrow. You can check out the following link and youtube videos in regard to the VariPLUS MODEL 105 below.

After all said and done, I am afraid that running the mixer at 50 Hz may not reduce the RPM low enough. According to the Santos manual, the motor speed at 50 Hz is 1450 RPM, which generates a fork speed of 70 RPM. This speed is not slow enough! I need a fork speed lower than, or at least, 45 RPM. Many prominent Italian fork mixers run below 45 RPM.

Hello,When I owned a 18 mixer (many years ago), I managed to change the speed quite easily.Its single phase motor was fitted with a permanent capacitor (instead of a starting capacitor which is disconnected since the rotor began to run), and this allowed me to drive it via a frequency inverter.But be carferul to not choose any model : theses devices are first of all made for 3 phase induction motors, but fews models are able to drive single phase motor which do not have transitional state when starting (i.e permanent capacitor)...

If the variable speed is not required, another solution would consist to replace de worm&wheel gears located inside the reducer. These gears are made of brass, and I suppose that any milling shop would be able to copy these gears but with a bigger reduction ratio.

The quick spec for this unit says 4.6 amps max. Bill/SFNM's Santos plate says 4.5 amps. Much too close for me, and will it handle the start surge of the Santos motor?

Dear Apizza, I do not know if the VariPlus Model 105 handles the start surge of the Santos motor. If the "start surge" is the same as "inrush current", the specifications below may hold an answer to your question. Good day!

Hello,When I owned a 18 mixer (many years ago), I managed to change the speed quite easily.Its single phase motor was fitted with a permanent capacitor (instead of a starting capacitor which is disconnected since the rotor began to run), and this allowed me to drive it via a frequency inverter.But be carferul to not choose any model : theses devices are first of all made for 3 phase induction motors, but fews models are able to drive single phase motor which do not have transitional state when starting (i.e permanent capacitor)...

If the variable speed is not required, another solution would consist to replace de worm&wheel gears located inside the reducer. These gears are made of brass, and I suppose that any milling shop would be able to copy these gears but with a bigger reduction ratio.

Dear Holorim, I thank you very much for your comments! Please, allow me to ask you a question. When you say "18 mixer", do you mean "Santos Mixer Model 18"? I will keep the "permanent capacitor" and "worm&wheel gears" in mind when I soon see a local armature specialist.

I talked to one such specialist over the phone today. Not having seen the motor in person, he suspected that the santos' single-phase, asynchronous/induction, capacitor-start motor has "four poles". And, he stated by adding four more poles, if possible, he can reduce the speed from 1800 RPM to 900 RPM, at the cost of over $1000.00 and possibly $3,000 dollars!

Not knowing anything about the Santos company, I would be too presumptuous in thinking that: the high price of designing a new motor leads me to speculate that perhaps when Santos decided to market the mixer here in the US, they introduced the old motor in the new market, rather than designing a new motor to fit the circumstances of the new market. Good night and thank you again!

Another local electric motor specialist just called me and told me the same thing as above. Price? "Possibly over $2,500 dollars". At this point, I am quite agitated. It is time to listen to the melancholic voice of Maria Callas to calm me down!

I'm going to guess the Variplus at 18 amps in rush will handle the start, but here is the real problem.

"After all said and done, I am afraid that running the mixer at 50 Hz may not reduce the RPM low enough. According to the Santos manual, the motor speed at 50 Hz is 1450 RPM, which generates a fork speed of 70 RPM. This speed is not slow enough! I need a fork speed lower than, or at least, 45 RPM. Many prominent Italian fork mixers run below 45 RPM"

So I wonder if you should put money into something that will not give the desired result. Perhaps this thread will produce a solution. I'm still thinking about it. An interesting problem.

Hi Omid,Yes I was talking about de Santos Mixer model 18, as you illustrated it with the exploded views above.Originally this brand was specialized in electric motors, but since it totally becomed a manufacturer in food machines, now the motors are contracted out (mainly the Société des Moteurs Electriques de Normandie).I can confirm you the motor is 4 poles (synchronous speed = 1800 rpm at 60Hz). Rewind it with 6 poles would reduce the synchronous speed at 1200rpm (and 900 with 8 poles), but unfortunalety this operation will be uncertain on a single-phase motor which is always engineered for only one optimal winding.In my opinion, its better to keep the actual motor, and to power it with a 3-phase inverter which can drive single-phase motor (i.e. Siemens Micromaster's range).

I'm going to guess the Variplus at 18 amps in rush will handle the start, but here is the real problem.

"After all said and done, I am afraid that running the mixer at 50 Hz may not reduce the RPM low enough. According to the Santos manual, the motor speed at 50 Hz is 1450 RPM, which generates a fork speed of 70 RPM. This speed is not slow enough! I need a fork speed lower than, or at least, 45 RPM. Many prominent Italian fork mixers run below 45 RPM"

So I wonder if you should put money into something that will not give the desired result. Perhaps this thread will produce a solution. I'm still thinking about it. An interesting problem.

Dear Apizza, you are quite right! That is exactly the thought I have been entertaining all day. I truly hope that the Santos makers TAKE NOTICE of all these posts we have been posting here. Yet, I still wonder how he did this: . Are we miscalculating or not fully examining our assumptions?

Hi Omid,Yes I was talking about de Santos Mixer model 18, as you illustrated it with the exploded views above.Originally this brand was specialized in electric motors, but since it totally becomed a manufacturer in food machines, now the motors are contracted out (mainly the Société des Moteurs Electriques de Normandie).I can confirm you the motor is 4 poles (synchronous speed = 1800 rpm at 60Hz). Rewind it with 6 poles would reduce the synchronous speed at 1200rpm (and 900 with 8 poles), but unfortunalety this operation will be uncertain on a single-phase motor which is always engineered for only one optimal winding.In my opinion, its better to keep the actual motor, and to power it with a 3-phase inverter which can drive single-phase motor (i.e. Siemens Micromaster's range).